Renewable fuse



Jan. 13, 1931. E. A. LAWRENCE.

RENEWABLE FUSE Filed March 25, 1928 "yon? Patented Jan. 13, 1931 UNITEDSTATES PATENTOFFICE EDWARD A. LAWRENCE, OF BELLEVUE, PENNSYLVANIA,ASSIGNOR TO GREAT wEs'rEnN FUSE COMPANY, or PITTSBURGH, PENNSYLVANIA, ACORPORATION OF DELAWARE RENEWABLE first: i

Application filed March 28, 1928. Serial No. 264,140.

The objects which I have in view are as follows The provision of anefficient renewable'fuse of simple construction and inexpensive tomanufacture.

The provision of a renewable fuse which may be quickly and convenientlyassembled and disassembled without requiring skill or the use of specialtools.

The provision of a renewable fuse whose ends are sealed against theoutward passage of flames along the terminal blades.

Other objects will appear from the following description.

In the accompanying drawings, wherein I have illustrated the bestembodiment of the principles of my invention now known 20 n e, Fig. 1 isa longitudinal section of the use.

Fig. 2 is an end View looking from the left in Fig. 1, and with thescrew cap omitted.

Fig. 3 is an inner face view of the anchoring washer. I

Fig. 4: is an edge view of the same.

Fig. 5 is an outer end view of one of the ferrules.

Fig. 6 is a side elevation of one of the terminal blades which isprovided with twin abutments. i

Fig. 7 is an edge view of the same. I

Fi 8 is an end view of the fuse withthe screw cap, the anchoring washerand the sealing disk removed and the terminal blade in position. i

Fig. 9 is an inner face ing washer. n

Fig. 10 is an edge view of the same.

Referring to the drawings, 1 indicates the tubular shell which is ofinsulating material, 40 such as fibre.

On each end of the. shell there is fixed a metal ferrule 2 secured inplace as by threaded engagement and riveting. The ferrules are providedwith recesses in their ends to form seats 3. The outer ends of theferrules are exteriorly threaded to receive the annular caps 4.

The shell 1 and the ferrules 2 comprise the tubular body of the fuse. 505 and 6 indicate the two metal terminal of the slotted sealmetricallydisposed slotted opening 15 which in place.

blades'whose reduced inner extremities are detachably connected to theends of the fusible link 7.

One of the terminal blades 5 is provided with a fixed circular closurehead 8 which engages and closes one end of the fuse body bearing againstthe outer end of the ferrule 2.

The head 8 is provided with a lug 9 on its inner face to engage the seat3 and hold the i embracing the terminal blade and closing the end oft-hefuse body.

The washer 11- is provided with a lug 13 on its inner face at the closedend of the slot 12, which lug engages the seat 3 and holds the washerand terminal blade against rotation relative to the fuse body. V

14 represents the metal sealing disk which is circular and ofsubstantially theisame diameter as the anchoring washer 11. Said disk isprovided-with a closed ended symis of proper dimensions to permit thedisk to be slippeddown over the terminal blade 6 to rest on the outerabutment 10.

The d sk 1st is. provided on its inner sur- "face with a lug 16sodisposed that it enters theopen end of the washer slot 12 and blocksthe same.

Theannular screw cap 4 is then screwed onto the ferrule clamping thedisk 14 down into sealing engagement with the abutment and holding theassembled elements rigidly WVhon the fuse is to be assembled the twoterminal blades are connected to the opposite .ends of the fusible linkand the terminal blade 6 and the link 7 are inserted through the rightend of the fuse body as shown in Fig. 1 until the closure head 8 seatson the end of the fuse body and its lug 9 engages the seat 3 in thecorresponding ferrule 2.

The anchoring washer is then slid laterally in place between the twoabutments 10 on the terminal blade 6 closing its adjacent end of thefuse body and its lug 13 engaging the seat 3 in the correspondingferrule 2.

The sealing diskis now slipped down over the end of the terminal blade 6against the outer abutment 10 with its lug l6 engaged in the slot 12 ofthe washer 11 and the cap 4 is screwed down snugly into place.

\Vhen it is desired to disassemble the fuse, the screw caps may beremoved and also the anchoring washer and the sealing disk, thusreleasing the parts.

It is evident from the foregoing description that the terminal blade iseffectively sealed against the outward travel of flames along the same.

It is further evident that my improved renewable fuse is of simple andinexpensive construction; comprises relatively few parts, and that itmay be assembled, disassembled and renewed by an unskilled person andwithout requiring tools.

\Vhat I desire to claim is 1. In a renewable fuse, the combination of atubular fuse body, a terminal blade arranged to extend through the endthereof and having a pair of spaced apart abutments fixed on said blade,and both extendingoutwardly from the flat sides of the blade, ananchorage washer having a slot open at one end and arranged to be slidlaterally between said abutments and embracing the blade and closing theend of the fuse body, said washer and fuse body having partsinter-engaging to prevent rotation of the washer relative to the body, asealing disk having a closed ended slot and slipped down over the end ofthe terminal blade to rest on the outer abutment, the outer abutmentbeing interposed between said Washer and said sealing disk, and theinner abutment overlapping and sealing the sides of the slot in theanchorage washer and means for clamping the parts to the end of the fusebody.

2. In a removable fuse, the combination of a tubular fuse body, aterminal blade arranged to extend through the end thereof and having apair of spaced apart abutments, fixed on said blade, an'anchorage washerhaving a slot open at one end and arranged to be slid between saidabutments and embracing the blade and olosin g the end of the fuse body,said washer and fuse body having parts interengaging to prevent therotation of the wash er relative to the fuse body, a sealing disk havinga closed ended slot and slipped down over the terminal blade to rest onthe outer abutment, the outer abutment being interposed between saidwasher and said sealing disk, said disk having a portion engaged in theslot of said washer, and means for clamping the parts to the end of thefuse body.

3. In a renewable fuse, the combination of a tubular fuse body, aterminal blade arranged to extend through the end of said body, a pairof parallel abutments fixedly mounted on said blade, and a one-piececlosure provided with an open ended slot for the end of the fuse bodyembracing said blade and engaged between said abutments, both of saidabutments overlapping the sides of the slot in said closure to aid insealing the same.

Signed at Pittsburgh, Pa., this 20th day of March, 1928.

EDWARD A. LAWRENCE.

